1. Field of the Invention
An aspect of the present invention relates to a recoil starker in which a rope reel is rotated by pulling a recoil rope wound therearound, and a rotation force of the rope reel is transferred to a clutch mechanism to start an engine via a damper spring.
2. Background Art
Generally, a speed adjustment unit equipped with a throttle lever is mounted on the pipe handle of a soil and vegetation management machine, such as a string trimmer, a rotary tiller, a rice transplanter or a lawn mower, and the rotation speed of an engine is controlled by adjusting the pulling amount of the throttle lever. For example, for a string trimmer, a throttle adjustment unit is mounted near a grip on a pipe handle to control the rotation speed of an engine. This throttle adjustment unit is so designed that an engine, such as a gasoline engine, is mounted on one end of a pipe handle, and a rotary blade to be driven by the engine is provided on the other end via a drive shaft fitted into the pipe handle.
A recoil starter for starting the engine can be provided on the pipe handle. A related-art recoil starter has a structure in which a rope reel and a cam member that serves as a clutch mechanism are elastically connected through a coil-shaped damper spring located therebetween, and in which the rotation force of the rope reel accumulated by pulling a recoil rope is transferred to the cam member via the damper spring. The rotational force transferred to the cam member can then be transferred to, and used to start, the engine (see, for example, JP-2006-132519-A).
According to the structure of the related-art recoil starter, a shaft portion is integrally formed with the starter case, and the rope reel and the bearing of the cylindrical cam member (around which the damper spring is wound) are rotatably supported on the shaft portion. Since the shaft portion is formed short, the shaft can not support the rope reel and the cam member along the entire lengths, and merely holds them along only one side. Further, while the starter case is secured to the crankcase of the engine, the shaft portion is not stably provided because it is located away from the crankcase. In addition, since the rope reel and the cylindrical cam member are arranged on the shaft portion of the starter case, high rigidity is required for the starter case to ensure smooth rotations.
When simply moving the shaft portion from the starter case side to the crankcase side, the recoil reel is positioned at the distal end of the shaft portion and protrudes from the crankcase. The damper spring is disposed between the recoil reel and the cam member that is to be positioned at the proximal end of the shaft portion. Since the damper spring is formed in a coil shape and requires a certain length, the rope reel is positioned at a distance from the crankcase. Therefore, the shaft and the supporting structure for the shaft must be formed rigidly.